Xu De-Xiang, Chen Yuan-Hua, Zhao Lei, Wang Hua, Wei Wei
Department of Toxicology, Anhui Medical University, Hefei, People's Republic of China.
Am J Obstet Gynecol. 2006 Dec;195(6):1707-14. doi: 10.1016/j.ajog.2006.03.047. Epub 2006 Jun 12.
Maternal infection is a cause of adverse developmental outcomes including embryonic resorption, intrauterine fetal death, and preterm labor. Lipopolysaccharide-induced developmental toxicity at early gestational stages has been well characterized. The purpose of the present study was to investigate the effects of maternal lipopolysaccharide exposure at late gestational stages on intrauterine fetal growth and skeletal development and to assess the potential role of reactive oxygen species in lipopolysaccharide-induced intrauterine fetal growth restriction and skeletal development retardation.
The timed pregnant CD-1 mice were intraperitoneally injected with lipopolysaccharide (25 to 75 microg/kg per day) on gestational day 15 to 17. To investigate the role of reactive oxygen species on lipopolysaccharide-induced intrauterine fetal growth restriction and skeletal development retardation, the pregnant mice were injected with alpha-phenyl-N-t-butylnitrone (100 mg/kg, intraperitoneally) at 30 minutes before lipopolysaccharide (75 microg/kg per day, intraperitoneally), followed by an additional dose of alpha-phenyl-N-t-butylnitrone (50 mg/kg, intraperitoneally) at 3 hours after lipopolysaccharide. The number of live fetuses, dead fetuses, and resorption sites was counted on gestational day 18. Live fetuses in each litter were weighed. Crown-rump and tail lengths were examined and skeletal development was evaluated.
Maternal lipopolysaccharide exposure significantly increased fetal mortality, reduced fetal weight and crown-rump and tail lengths of live fetuses, and retarded skeletal ossification in caudal vertebrae, anterior and posterior phalanges, and supraoccipital bone in a dose-dependent manner. Alpha-phenyl-N-t-butylnitrone, a free radical spin-trapping agent, almost completely blocked lipopolysaccharide-induced fetal death (63.2% in lipopolysaccharide group versus 6.5% in alpha-phenyl-N-t-butylnitrone + lipopolysaccharide group, P < .01). In addition, alpha-phenyl-N-t-butylnitrone significantly reversed lipopolysaccharide-induced intrauterine growth restriction and skeletal development retardation. However, aminoguanidine, a selective inhibitor of inducible nitric oxide synthase, had little effect. Furthermore, lipopolysaccharide-induced intrauterine fetal death, intrauterine fetal growth restriction, and skeletal development retardation were associated with lipid peroxidation and glutathione depletion in maternal liver, placenta, and fetal liver. Alpha-phenyl-N-t-butylnitrone significantly attenuated lipopolysaccharide-induced lipid peroxidation and glutathione depletion in maternal liver, placenta, and fetal liver.
Maternal lipopolysaccharide exposure at late gestational stages results in intrauterine fetal growth restriction and skeletal development retardation in mice. Reactive oxygen species might be, at least in part, involved in lipopolysaccharide-induced intrauterine fetal growth restriction and skeletal development retardation.
母体感染是导致不良发育结局的原因之一，包括胚胎吸收、宫内胎儿死亡和早产。脂多糖在妊娠早期诱导的发育毒性已得到充分表征。本研究的目的是调查妊娠晚期母体暴露于脂多糖对宫内胎儿生长和骨骼发育的影响，并评估活性氧在脂多糖诱导的宫内胎儿生长受限和骨骼发育迟缓中的潜在作用。
在妊娠第15至17天，对定时受孕的CD-1小鼠腹腔注射脂多糖（每天25至75微克/千克）。为了研究活性氧在脂多糖诱导的宫内胎儿生长受限和骨骼发育迟缓中的作用，在脂多糖（每天75微克/千克，腹腔注射）前30分钟给妊娠小鼠注射α-苯基-N-叔丁基硝酮（100毫克/千克，腹腔注射），随后在脂多糖注射后3小时再注射一剂α-苯基-N-叔丁基硝酮（50毫克/千克，腹腔注射）。在妊娠第18天计算活胎、死胎和吸收部位的数量。称量每窝活胎的体重。检查顶臀长度和尾长，并评估骨骼发育。
母体暴露于脂多糖显著增加了胎儿死亡率，降低了活胎的体重、顶臀长度和尾长，并以剂量依赖的方式延缓了尾椎、前后指骨和枕上骨的骨骼骨化。自由基自旋捕获剂α-苯基-N-叔丁基硝酮几乎完全阻断了脂多糖诱导的胎儿死亡（脂多糖组为63.2%，α-苯基-N-叔丁基硝酮+脂多糖组为6.5%，P<.01）。此外，α-苯基-N-叔丁基硝酮显著逆转了脂多糖诱导的宫内生长受限和骨骼发育迟缓。然而，诱导型一氧化氮合酶的选择性抑制剂氨基胍几乎没有效果。此外，脂多糖诱导的宫内胎儿死亡、宫内胎儿生长受限和骨骼发育迟缓与母体肝脏、胎盘和胎儿肝脏中的脂质过氧化和谷胱甘肽耗竭有关。α-苯基-N-叔丁基硝酮显著减轻了脂多糖诱导的母体肝脏、胎盘和胎儿肝脏中的脂质过氧化和谷胱甘肽耗竭。
妊娠晚期母体暴露于脂多糖会导致小鼠宫内胎儿生长受限和骨骼发育迟缓。活性氧可能至少部分参与了脂多糖诱导的宫内胎儿生长受限和骨骼发育迟缓。
